describes how to configure the maximum Excess Information Rate (EIR) ratio
between the BE bandwidth among adjacent BGs.
The EIR ratio is
used to maintain the maximum EIR bandwidth difference between BGs. It helps to
prevent BGs (which has only a few active BE service flows) from getting very
low or zero EIR bandwidth. Otherwise, these BGs will not be able to admit CIR
flows as they get only very low EIR bandwidth.
there are two BGs sharing the same RF channel, with BG1 having 1000 active BE
service flows and BG2 having none. If “max-eir-ratio” is not used, BG1 gets all
the bandwidth leaving no bandwidth for BG2. When a voice CIR tries for
bandwidth at BG2, it will get rejected. If “max-eir-ratio” is set at 10, BG2
gets about 10 percent of the QAM that is sufficient to admit the voice CIR. The
‘max-eir-ratio’ is a trade-off between perfect fairness and CIR utilization. It
means, compromising 'flow fairness' to prevent some BGs from getting all the
bandwidth leaving the other BGs with none.